Self-arming projectile



Dec. 20, 1955 F. PERLIN 2,727,464

SELF-ARMING PROJECTILE Filed Dec. 8, 1951 I WW? United States Patent()SELF-ARMIN G PROJECTILE Fred Perlin, Edgerton, Wis., assiguor to TheParker Pen Company, Janesville, Wis., a corporation of WisconsinApplication December 8, 1951, Serial No. 260,678 3 Claims. (Cl. 102-38)The presentinvention relates to self-arming, explosive projectiles andparticularly to a self-arming projectile especially well-adapted for usein connection with small arms. i

'Ihe projectile is of such character as to be adaptable primarily tofixed charge cartridges, and although the projectile` is intendedparticularly for use with small arms, its construction enables itsadaptation to Weapons of any caliber utilizing lixed charge cartridges.

An object of the invention is to provide a self-arming, explosiveprojectile adapted fortuse in a cartridge having a case of commonconstruction such as used in heretofore well-known cartridges, whichprojectile has a smooth and substantially unbroken outer surface.

A still further object is the provision of a cartridge includingyaself-arming, explosive projectile that is positively disarmed.

Another object is the provision of a cartridge including a self-arming,explosive projectile having no exposed parts other than the casing ofthe projectile, in which the projectileis not likely to be damaged inthe handling of the cartridge preparatory to tiring. l

Still l:another object is the provision of a self-arming, explosiveprojectile having substantially no change in shape as compared with acommon solid bullet.

A further object is the provision of a self-arming, explosiveyprojectile of novel construction for use primarily in connection withsmall arms, which is of such charac- 'ter as to enable it to be used asa spottinground or as an explosive round.

Another object is to provide an explosive projectile of novelconstruction for use in a .fixed charge cartridge which' is put indisarmed condition in the manufacture of the cartridge and remains sodisarmed by means of the cartridge case in engaging the projectile, andwhich is automatically armed upon its leaving the cartridge case and thebarrel of the weapon from which it is tired.

Another object is the provision of a novel projectile of the foregoingcharacter that is initially disarmed and re mains disarmed until fired,whereupon it immediately becomes armed, eliminating the necessity formanual manip,- ulation for the purpose of arming the projectilepreparatory to tiring it. j

A further object is the provision of a self-arming projectile having aninertia-actuated priming or detonating element in which, when theprojectile is in disarmed condition, the detonating element ispositively locked against relativemovement such as to cause detonationof the chargein the projectile.

`Sti1l another object of the invention is the provision of a projectilefor use in a fixed charge cartridge, having an inertia-actuateddetonating element contained entirely within the interior of theprojectile, and means for posi- `tively locking the detonating element`in disarmed position, in which the locking'means is maintained ineffective position by the cartridge case.

Another object is the provision of a projectile having an ,ignitablecharge therein, for use in a cartridge having an ignitable propellingcharge, in which the interior of the projectile is sealed from theinterior of the cartridge case for preventing propagation of ignitionfrom the propellant in the cartridge case to the charge in theprojectile. v

A further object is to provide a self-arming projectile of simple andinexpensive construction. i

Further objects will appear upon reference to the following detaileddescription taken in conjunction with the accompanying drawing, inwhich:

Figure 1 is a fragmentary longitudinal sectional view of the projectileand forward portion of the cartridge case with which it is used; and

Fig. 2 isan enlarged transverse sectional view taken on line 2 2 of Fig.1.

The projectile and cartridge case illustrated in the drawing togetherform a fixed round or cartridge. The projectile is shown as a whole at10 and the cartridgecase at 12. The cartridge case 12 may be of` anysuitable known form and construction and includes arrear tubular portion14 containing an ignitable propelling charge 16 which may be of anysuitable material effective for propelling the projectile from theweapon in which the ammunition is used. The cartridge case 12, as isusual, includes 'a percussion cap (not shown) at the rear for ignitingthe propelling charge. The forward end of the cartridgecasei12 is ofreduced diameter as indicated at 18 for engaging and gripping theprojectile 10 and surrounding the rearward portion thereof as iscustomary in fixed charge cartridges. The cartridge case is of commoncone struction such as used in heretofore well-known cartridges andneedliave no special features of construction made necessary by reasonof its cooperation of the projectile of the present' invention.

In a lixed charge cartridge the propelling charge is preplaced in themanufacture of the cartridge and it cannot thereafter be altered, thecase of the cartridge being securely tted on the projectile as by meansof a press fitting operation or other desired operation elfective forretaining the case and projectile in assembled condition and preventingremoval of the projectile from the case except when the cartridge istired.

The projectile 10 as illustrated is in disarmed condition, it being somaintained by the cartridge case. The projectile includes a shell orcasing 20 made up of an outer jacket member 22 and an inner, linermember 24 shaped complementally to the outer element throughout thegreater part of its area. The liner member preferably is formed fromsteel but other material may be used. The jacket member 22 may be formedof anysuitable metal and has a smooth outer surface (except for smallapertures to be referred to later), including a tapered forward end 26terminating in a rounded small `dimension nose 28. The overall shape ofthe projectile and its smooth outer surface as determined by the jacketmember 22 are effective for minimizing air resistance. The liner member24 terminates forwardly in a flattened end 30 which is accordinglyspaced rearwardly from the nose 28 of the outer jacket member 22. Theattened portion 30 is provided with an aperture for receiving a screw orpin 32 having va roughened or threaded portion 48, as will be referredto later, and having a head 34 for engaging the outer surface of theflattened p ortion 30 for establishing a reaction point for the screw inthe function of the latter in securing certain elements of theprojectile together. The screw 32 extends longitudinally through theprojectile and its rear threaded end 36 is threaded into a complementarythreaded aper-v ture in a closure plate or backing member 38 whichcloses the rear end of the casing or hollow member 20. The plate orbacking member 38 may have a reduced diameter portion 40 for extendinginto the liner 24 and a ange 42 agarose for ,engaging .the end. edge. ot.tlreliner -2dr the flange preferably being of a diameter equal to theouter diameter of the inner element 24 'so that it fits within thejacket memherrZZ.. 'the latterbeing .extended rearwardly' anappropriatedistance. for accomplishing that. purpose. The plate orbacking member 3d may be press .fitted in the liner Zit or sweated orotherwise titted therein so as to seal the interior of the projectileagainst the propagation .of ignition thereinto from the. propellingcharge in the cartridge case 12. The screw 52 on being tightened downinto the plateor backing member 38 secures the backing member to theliner member 24 in an effectively integral arrangement. The jacketmember 22 may be secured against neasy removal from the liner Z4 in anappropriate manner such as providing relative .dimensions of the twoelements for retaining them together by friction.

The projectile of the present invention may be utilized in connectionwith spotting operations, in which case it is so constructed as. toprovide a arefor visually indicating the target location oftheproiectile upon impact. When the projectile is intended to be usediorsuclr purposes, it is provided with an ignitable charge and provisionis accordingly made for producing ignition` in the projectileupollimpaot with the target. The particular means for producingsuchignition will be referred to later.

When the projectile is to be used in spotting operations, achargc 4,4that. is capable of being ignited is employed. Anywell-known materialeiective for`producing a bright are'or other .visible signal may beemployed. Such materials are well known to those skilled in the art andit is believed unnecessary to Specify particular materials. The charge44 is placed adjacent the forward end vof the Rroiectile, andyrearwardly thereof .is a priming, igoiting or detonatingchargeflo'capable of being igrlited Yby a spark and propagatingthe ignition tothe spotting charge f4.4. The charge 'd6 is loosely packed and capableof being compacted into a relatively small volume, for enabling thedesired movement ot the. inertia-actuated detonating member as will bedescribed later.

-Wlien the projectile is to. be used as an explosive missile, thechargelfi is of. high explosive character, and an ignitable .detonatingCharge is employed of such charac with a .central aperture 5ft for.receiving die @prev 3:? The drive member is arranged for movementlongitudinally of the projectile when the projectile is in armedcondition, but has a disarmed position adjacent the rear end of theprojectile, such disarmed position being illustrated in the drawing. Forthe purpose of mounting the pyrophoric element 52,' the forward face ofthe drive member ist, provided with an annular recess 56 in which thepyrophoric elerrentuis 'mounted the latter being molded in the recessinv an appropriate operation., The pyrophoric elementalso is provided.with a central aperture for receiving the screw 3,12 and thus surroundsthe Scw .Y

In the disarmed position. of .the drive member 50 as shown in thedrawing, the element S2 is disposed rearwardly of the roughened portion43, but is arranged for engaging and rubbing on the latter upon relativeforward movement in the projectile when so moved by inertia upon ter` asto .cause detonation of the explosive charge in response to ignition o fthe detonation. Accordingly, the charge 44 will be referred to as anexplosive charge. The termtexplosivei as used herein will be. understoodto include explosives in the broad general senseand includes not onlyhigh explosives but also low explosives and burning compositionssuitable fonspotting charges, as

for example black powder and known incendiary materialsv Similarly,detonationt will be understood .to in elude .detonation of.the-character associated with high explosives aswell as .the action ofproducing ignition vot burning compositions such. as those mentioned. v

The` screw 32. is. provided with a threaded, serrated or otherwiserougllened portion 48 .for aiding in producing an ignition spark. Thethreaded portion 48 preferably is provided with relatively sharp outeredges for the purpose ,of readily producing .the .spark intended. Theroughened portion is ot course preferably disposed adjacent the primingor detonating charge 46 and inthe specific illustration is-irnniediatelyembodied in that charge. This roughened portion is, also spacedforwardly from the rear end of the projectile to insure against possibleaccidental ignition of the charge 46 when the projectile is in disarmedcondition, .as will be apparent as the description proceeds.

-... The projectile is designed for producing an ignition .spark uponimpact with the target, the Spark being caused by an inertia-actuatedelement which in the specific illustrationtalies the form of a drivemember 5.0 provided with a flinttype pyrophoric element 52 capable ofproducing a spark-l when rubbed by or on a rough surface. The

sudden deceleration of the projectile as in impact .with the target. Thecharge 46 being loosolypacked, as above mentioned, enables it to becompacted into a relatively small volume for enabling relative forwardmovernentof the drive member in the projectile, whereby the element 52engages and rubs on vthe roughened portion 48 and causes a spark forigniting .the charge 46. The drive member S0 is positively locked in itsdis.- armed condition by means of a pairof pins 58 which in turn aremaintained in locking position by the portion 18 of the'cartri'dge case.These pins 58 which may consist of two or more `in number tit ratherloosely in and extend through apertures t6@ in the two members 22 and 24of the projectile casing Zii. These apertures, as will be noted, aredisposed adjacent the rear end of the projectile, so' that when thedrive member Si) is in its disarrned position the latteroverll theapertures. The pins are 'of appropriate length to extendk inwardlybeyondthe element 24 and into engagement with the .drive member. The drivemem.- ber isprovided With means such as a peripheral groove 62, orsocket if desired, for receiving the inner ends of the Pitts. ,Such aperipheral groove is -advantag.eous as'co'mpared with individualsockets, since when a peripheral groove is utilized the drive memberneed not be set in vany predetermined angular position for receiving`the pins.

The projectile is mounted in the cartridge .case 12 in such positionthat the rear end portion of the projectile 's received in andsurrounded by the reduced portion 18 of the case l2 wherein the portion18 covers the apertures 60 andthe pins 5,8 and retains the latter in theapertures. The pins being Qfappropriate length to extend into the grooved2 positively leek thedrive member .50 in its disarrned po.- sition so.that as long es the projectile remains mounted in the Cartridge case, asit will be et all times before tiring, the possibility of accidentallyexploding the charge in Atlne pro: iectile is eliminated; I

Since the pins lit loosely in the apertures .60 and groove .62. they arereadily removable therefrom in re.- sponse to centrifugal force of theprojectile due to its rotation by the riing of the weapon from which itis fired.

drive member 50 may be made of any desired material A having Asubstantial mass and has an overall cylindrical `'shapefo'frelativelyshort axial dimension-and provided Thus, upon firing of the cartridgeand the projectile leaving the cartridge case, the pins 5S arc thrownoutwardly and the drive member Sil is enabled to move relativelyV,forwardly in the projectile uponidecelerationof the projectile onirripact ,with the target. As explained above, v relativeforward-movement of the drive rr'ilembericausels bingv of the pyrophoricelement on thrmaded .or roughened surface 4,8 producing awspa'rk andvignitling the'charge which in'turn V sets off the charge is of coursedesirable that the .pins 5S are not thrown out of their apertures untilthe projectile leaves the barrel of die. weapon from. which it istired,- .It will bereedily understood that the length ofthe pins may besuch as to prevent such action. The portion 18 of the shell caseis-brought into such tight fitting engagement lwith the projectile as'toprevent propagation or' transmission of ignition from the interior ofthe cartridge case through the apertures 60 into the interior of theprojectile.

The outer surface of the projectile is substantially smooth, beingbroken only by the very small aperture 60 whereby air resistance fromthis source is negligible.

I claim:

1. A self-arming projectile for use with a cartridge case containing apropelling charge and having an open forward end, said projectileincluding a casing having an imperforate forward end and containing anignitable spotting charge and an igniting charge therein, the projectilehaving an opening in its side Wall adjacent its rear end and beingadapted for mounting of its rear end portion in the open end of acartridge case in such position that the cartridge case covers saidopening, an inertia-actuated drive member mounted for longitudinalmovement in the casing and having a disarmed position adjacent the rearend thereof in overlying relation to said opening, said drive memberincluding a dint type pyrophoric element and having a central aperture,locking means mounted in said opening projecting into engagement withsaid drive member for locking the drive member in its disarmed position,said locking means being positioned for retention in said opening by acartridge case when the projectile is mounted therein and being readilyremovable outwardly from the opening upon the removal of the projectilefrom the cartridge case, and a central stem in the projectile casingwith its forward end entirely within the casing and its rear endextending through the aperture in said drive member and having aroughened friction surface positioned for cooperation with saidpyrophoric element for igniting said igniting charge in response torelative forward movement of the drive member.

2. A cartridge having a self-arming projectile, comprising a cartridgecase containing a propelling charge and having an open forward end, saidprojectile including a hollow casing containing an ignitable charge andhaving an imperforate forward end and an open rear end, said casinghaving a side opening adjacent its rear end, the projectile having itsrear end portion mounted in the open end of the cartridge case in suchposition thatl the cartridge case covers said side opening, a plateclosing the open rear end of said hollow casing, a longitudinal memberin the projectile casing with its forward end connected to the casingwithin and adjacent the forward end of the casing and to said plate forsecuring the plate to the casing, said longitudinal member having aroughened surface portion, a drive member in the casing movablelongitudinally therein with a central opening receiving saidlongitudinal member and having a pyrophoric element engageable with saidroughened surface, said drive member having a disarmed position adjacentthe rear end of the casing wherein said pyrophoric element is disposedrearwardly of said roughened surface and the drive member overlies saidside opening, and locking means mounted in said side opening extendinginto engagement with said drive member for locking the drive member inits disarmed position, said locking means being retained4 in said sideopening by the cartridge case when the projectile is mounted therein andbeing readily removable therefrom upon removal of the projectile fromthe cartridge case.

3. A cartridge having a self-arming projectile, comprising a cartridgecase containing a propelling charge and having an open forward end, saidprojectile including a hollow casing made up of an outer jacket elementand an inner complementally shaped element telescoped together andtogether having an open rear end, a plate closing said open rear end,said hollow casing having radially disposed apertures in its rear endportion, the projectile having its rear end portion mounted in the openend of the cartridge case in such position that the cartridge casecovers said apertures, said projectile casing containing an explosivecharge in its forward portion and a detonating charge rearwardly of theexplosive charge, and having a tapered forward end, and the innerelement of the casing having a flattened forward end spaced from theforward end of the outer element, a longitudinal member connected to theforward end of said inner element and said plate for securing the plateto the hollow casing and having a roughened surface adjacent saiddetonating charge, a drive member mounted in said casing for movementlongitudinally therein with a central opening receiving saidlongitudinal member and having a flint type pyrophoric elementsurrounding the longitudinal member adapted to engage and rub on saidroughened surface in response to relative forward movement of the drivemember, said drive member having a disarmed position adjacent the rearend of the casing overlying said apertures and with said pyrophoricelement rearwardly of said roughened surface, and locking pins mountedin said apertures extending into engagement with said drive member forlocking the drive member in its disarmed position, said pins beingretained in the apertures by said cartridge case and being freelyremovable therefrom by centrifugal force upon rotation of the projectileafter its removal from the cartridge case.

References Cited in the tile of this patent UNITED STATES PATENTS 45,024Cleu Nov. l5, 1864 480,142 Schlorl Aug. 2, 1892 2,217,645 Wilde et alOct. 8, 1940 2,390,552 Nelson Dec. 1l, 1945 2,452,072 Schatz Oct. 26,1948 FOREIGN PATENTS 400,005 Italy Nov. 23, 1942

